Securing Sendmail with Cyrus - Sanity Check: I've configured sendmail 8.12.2, to "RunAsUser" user -> "cyrus" rather than "root". Please look over the following "sendmail.cf" excerpts and directory ownership and permissions. Do these configs make sense? Is this environment Secure? What other recommendations are suggested?
. . . # what user id do we assume for the majority of the processing? O RunAsUser=cyrus . . . Mlocal, P=/usr/bin/procmail, F=lsDFMAw5:/|@qSPfhn9, S=EnvFromL/HdrFromL, R=EnvToL/HdrToL, U=root:cyrus, T=DNS/RFC822/X-Unix, A=procmail -Y -a $h -d $u . . . ################################################## ### Cyrus Mailer specification ### ################################################## ##### $Id: cyrus.m4,v 8.22 2000/09/02 17:46:43 ca Exp $ (Carnegie Mellon) ##### Mcyrus, P=/usr/cyrus/bin/deliver, F=lsDFMnPqAh5@/:|, S=EnvFromL, R=EnvToL/HdrToL, U=cyrus:mail, T=DNS/RFC822/X-Unix, A=deliver -e -m $h -- $u Mcyrusbb, P=/usr/cyrus/bin/deliver, F=lsDFMnPu, S=EnvFromL, R=EnvToL/HdrToL, U=cyrus:mail, T=DNS/RFC822/X-Unix, A=deliver -e -m $u Mcyrus, P=[IPC], F=lsDFMnqA@/:|SmXz, E=\r\n, S=EnvFromL, R=EnvToL/HdrToL, T=DNS/RFC822/X-Unix, A=FILE /var/imap/socket/lmtp . . . Queue Directory permissions: drwxrwx--- 2 cyrus mail 4096 Apr 1 09:17 clientmqueue drwxr-x--- 4 cyrus mail 4096 Mar 25 16:31 imap drwxr-x--- 3 cyrus mail 4096 Mar 26 08:57 imap-news drwx------ 2 cyrus amavis 4096 Apr 1 13:57 mqamavis drwx------ 2 root cyrus 4096 Dec 10 11:28 mqueue I know that the above configuration works however, I'm specifically, curious about the "local mailer" -> "procmail" configuration. Is a potential security hole created by executing the local mailer as "root"? Your assistance in this matter is appreciated - Thanks! RB